Error analysis of reconstructed wave force on a circular cylinder by using wave elevation data

Abstract This paper presents a study on reconstruction errors of wave force around a circular cylinder using measured wave elevation data through theoretical analysis and experimental validation. Since the accuracy of reconstructed results is directly subjected to the collected data of wave elevation, some unexpected errors can be injected into the results as the data are not informative enough. A mathematical analysis is presented first, which considers the wave gauges uniformly distributed around the cylinder with the number of three, five, seven and nine. Amplitude error and phase error of the reconstructed wave force are defined to quantify the effect of distribution and number of wave gauges. An experiment was conducted to validate the theoretical results for both amplitude and phase errors. It shows that experimental data with three wave gauges can be well predicted by using theoretical analysis. Based on the theoretical results, an amended method is proposed to improve the reconstructed results with three wave gauges. The amended method is proved by the test data to be an efficient method in some specific situations. Finally, a comprehensive discussion on the difference between two kinds of processing method of the reconstructed wave force is performed.